Former teacher, site admin, district admin & edtech CERO with PhD in ed.

Good ones! I've always loved these:
"I touch the future. I teach." - Christa McAuliffe
"Our progress as a nation can be no swifter than our progress in education." - John F. Kennedy
"The educated differ from the uneducated as much as the living from the dead."- Aristotle

There are so many good quotes, but this one seems particularly interesting and shows that education is about having students somehow get to their own potential, innate abilities. Coming from Galileo gives these words some extra credibility!
"You cannot teach a man anything; you can only help him find it within himself."
Galileo Galilei

My all time favorite:
"The best thing for being sad," replied Merlin, beginning to puff and blow, "is to learn something. That's the only thing that never fails. You may grow old and trembling in your anatomies, you may lie awake at night listening to the disorder of your veins, you may miss your only love, you may see the world about you devastated by evil lunatics, or know your honour trampled in the sewers of baser minds. There is only one thing for it then -- to learn. Learn why the world wags and what wags it. That is the only thing which the mind can never exhaust, never alienate, never be tortured by, never fear or distrust, and never dream of regretting. Learning is the only thing for you. Look what a lot of things there are to learn."
T.H. White, The Once and Future King.
He wants to convey that learning have no age, gain knowledge from anywhere possible and make yourself a learning center.